Navies all around the world are filled with traditions, some dating back hundreds of years. Many of these traditions are so old that their origins have long been forgotten, but the reason why sailors have exactly 13 buttons on their trousers has a known explanation.
These bellbottom trousers, nicknamed “Crackerjacks,” were introduced with the US Navy in the early 1800s and were designed entirely for practicality. The flared ends were better suited for rolling up during laborious tasks. In addition, if a sailor was to fall overboard, the thick-wool trousers would quickly become extremely heavy. The flared bottoms made them easier to remove without taking off any footwear.
Some theories suggest the flared bottoms were simply implemented to give sailors a unique appearance.
The crotch area of the trousers features a flap called the “broadfall” and 13 buttons keep the broadfall in place. At the time the zipper was not commonplace on clothing, and even if it was, it would have rusted in the salty air sailors are exposed to.
Why 13 buttons?

The broadfall is held in place by exactly 13 buttons, a number that is often said to represent the United States’ original 13 colonies. This explanation is untrue.
Originally the broadfall had 15 buttons, but the Navy reduced this to just seven to save material. However, sailors soon complained that the broadfall was too small. This is partly because diet changes increased sailors’ size, and because the smaller flap was uncomfortable for their “equipment”.
The Navy listened and made the broadfall bigger. With more material came the need for more buttons, resulting in six more being added bringing the total to the 13 we have today. This number was probably chosen to maintain visual symmetry.
Other pieces of the uniform had their uses too.
For example, the neckerchief could be used as a headband or a cleaning cloth. It also kept their uniforms clean. This was because sailors in the 19th century often sported long hair. To keep their hair out of the way during tasks it would be tied in a ponytail and stuck down with a sticky tar-like substance. The neckerchief kept this off the rest of their uniform.
Like the “13 buttons 13 colonies” explanation for the bellbottom trousers, the neckerchief also has an alternative and equally unlikely origin. Allegedly the piece of fabric is a symbol to honor Admiral Lord Nelson, with the three white lines representing his three major victories.
Today the uniform is for dress rather than actual work, but these features have been retained to maintain traditions.